#include <func.h>

int main()
{
    int fd = open("file_mmap", O_RDWR);
    char *p = (char *)mmap(NULL, 5, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
    strcpy(p, "hello");
    munmap(p, 5);
    return 0;
}